JJWT is a 'clean room' implementation based solely on the [JWT](https://tools.ietf.org/html/draft-ietf-oauth-json-web-token-25), [JWS](https://tools.ietf.org/html/draft-ietf-jose-json-web-signature-31), [JWE](https://tools.ietf.org/html/draft-ietf-jose-json-web-encryption-31) and [JWA](https://tools.ietf.org/html/draft-ietf-jose-json-web-algorithms-31) RFC draft specifications.
Most complexity is hidden behind a convenient and readable builder-based [fluent interface](http://en.wikipedia.org/wiki/Fluent_interface), great for relying on IDE auto-completion to write code quickly. Here's an example:
This release adds convenience methods to the `JwtBuilder` interface so you can set claims directly on the builder without having to create a separate Claims instance/builder, reducing the amount of code you have to write. For example, this:
But you couldn't easily determine if the `jwt` was a `JWT` or `JWS` instance or if the body was a `Claims` instance or a plaintext `String` without resorting to a bunch of yucky `instanceof` checks. In 0.2, we introduce the `JwtHandler` when you don't know the exact format of the compact JWT string ahead of time, and parsing convenience methods when you do.
If you do not know the format of the compact JWT string at the time you try to parse it, you can determine what type it is after parsing by providing a `JwtHandler` instance to the `JwtParser` with the new `parse(String compactJwt, JwtHandler handler)` method. For example:
```java
T returnVal = Jwts.parser().setSigningKey(key).parse(compact, new JwtHandler<T>() {
@Override
public Object onPlaintextJwt(Jwt<Header,String> jwt) {
//the JWT parsed was an unsigned plaintext JWT
//inspect it, then return an instance of T (see returnVal above)
}
@Override
public Object onClaimsJwt(Jwt<Header,Claims> jwt) {
//the JWT parsed was an unsigned Claims JWT
//inspect it, then return an instance of T (see returnVal above)
}
@Override
public Object onPlaintextJws(Jws<String> jws) {
//the JWT parsed was a signed plaintext JWS
//inspect it, then return an instance of T (see returnVal above)
}
@Override
public Object onClaimsJws(Jws<Claims> jws) {
//the JWT parsed was a signed Claims JWS
//inspect it, then return an instance of T (see returnVal above)
}
});
```
Of course, if you know you'll only have to parse a subset of the above, you can use the `JwtHandlerAdapter` and implement only the methods you need. For example:
```java
T returnVal = Jwts.parser().setSigningKey(key).parse(plaintextJwt, new JwtHandlerAdapter<Jwt<Header,T>>() {
@Override
public Object onPlaintextJws(Jws<String> jws) {
//the JWT parsed was a signed plaintext JWS
//inspect it, then return an instance of T (see returnVal above)
}
@Override
public Object onClaimsJws(Jws<Claims> jws) {
//the JWT parsed was a signed Claims JWS
//inspect it, then return an instance of T (see returnVal above)
If, unlike above, you are confident of the compact string format and know which type of JWT or JWS it will produce, you can just use one of the 4 new convenience parsing methods to get exactly the type of JWT or JWS you know exists. For example:
JJWT depends on Jackson 2.4.x (or later). If you are already using a Jackson version in your own application less than 2.x, for example 1.9.x, you will likely see [runtime errors](https://github.com/jwtk/jjwt/issues/1). To avoid this, you should change your project build configuration to explicitly point to a 2.x version of Jackson. For example:
